This group of projects dealing with several facets of child health in the community is intended to provide a sound base for the identification of health and health-related problems of children in a typical community of 750,000 and to delineate, through experimental trials where possible, potential solutions to these problems. In addition to maintaining a data base (utilizing insurance and Medicaid payment files) to assist in monitoring community-wide changes and the effects of both planned and unplanned experiments on a large scale, the projects focus attention on the following specific areas: reproductive behavior (with special emphasis on teenage mothers); the modification of child rearing behavior (of parents of pre-school children); the modification of health (preventive) behavior of parents and children in relation to accident prevention and nutrition; and the care of children with chronic physical disorders (with emphasis on secondary and tertiary prevention of psychosocial complications).